1. Field of the Invention
The invention concerns a rotor for a rotary electrical machine that comprises two parallel magnet wheels that extend radially with respect to a principal axis of the rotor, each of which comprises a series of axial teeth, roughly trapezoidal in shape, that extend axially from the external radial end edge of the said-magnet wheel, in the direction of the other magnet wheel, so that each tooth on a magnet wheel is situated in the space existing between two consecutive teeth on the other magnet wheel, and that comprise magnetic elements, such as permanent magnets, each of which is arranged between two adjacent teeth each belonging to one of the two magnet wheels, and is received partly in a groove produced in each of the opposite lateral faces of the said two adjacent teeth, so that at least one of the two lateral faces of a first tooth of the said-two adjacent teeth comprises a groove in which a magnetic element is partly received, and so that each groove that is produced in a lateral face of a tooth of a rotor emerges at a first axial end of the tooth, where the first tooth is connected to the external radial end edge of the magnet wheel, or at a second free axial end of the tooth. The number of magnetic elements may be less than the number of teeth on a magnet wheel.
2. Description of the Related Art
According to a known embodiment, the two grooves that are produced in two opposite faces of two adjacent teeth are produced by means of a single tool, for example a milling cutter, after the two magnet wheels of the rotor have been mounted on a central shaft of the rotor.
It is also known how to produce all the grooves in the rotor so that they emerge at the same axial end of the rotor.
Consequently, when the two lateral faces of one and the same tooth on a pole wheel each comprise a groove receiving a magnetic element, the two grooves emerge axially either at a first axial end of the tooth where the tooth is connected to the edge of the radial end of the magnet wheel, or at the free axial end of the tooth, also referred to as the tip of the tooth.
The first axial end of the tooth, also referred to as the base of the tooth, where the tooth is connected to the magnet wheel, is then made less resistant to deformation when the two grooves in the tooth emerge at this base of the tooth, compared with an embodiment according to which the two grooves emerge at the free axial end of the tooth.
Thus, when the rotor is rotated at high speed, the reduction in the resistance to deformation of the base of the tooth means that the tooth deforms radially with respect to the rotor, and there is then a risk that the tooth may come into contact with the stator of the rotating electrical machine.
What is needed, therefore, is an improved rotor that overcomes one or more of the problems and risks of the prior art.